In container treatment systems, containers, such as bottles, cans etc., are treated in one or a plurality of successive processing steps. In so doing, the processing steps or working steps are generally carried out in separate treatment units, which may e.g. be combined as modules of a joint system concept. In order to reduce costs for the acquisition and the operation of the system, interfaces for controlling the system, for media supply or the like, are normally standardized so that treatment units of different types and/or production capacities can be combined more easily. A container treatment system for plastic bottles consisting e.g. of polyethylene terephthalate (PET), polypropylene (PEP), etc., may comprise e.g. a heating device for heating the parisons, a stretch blow molding device for expanding and stretching the parisons so as to obtain plastic bottles, a cleaning device, a labeler, a filler, a sorter, a packaging device, a sterilization device, an inspection device, a tempering device, a cooling device, a coating device, a buffer device, etc., as separate, modular treatment units. In the prior art, the individual treatment units, which carry out successive processing steps, are generally connected in series one after the other, and one or a plurality of conveying devices conveys the containers from the treatment units to the respective treatment units following downstream thereof.
The execution of successive processing steps by the separate treatment units of the system as well as the conveyance between the individual treatment units thus correspond to the known principle of assembly-line processing, where it is accomplished, by means of suitable control processes concerning the processing duration of the individual processing steps and/or the quantity of containers conveyed per unit time from one treatment unit to the next, that containers to be treated pass continuously through the successively arranged treatment units. In systems known from the prior art, the conveyance of the containers between the treatment units is often realized by means of a plurality of separate conveyor elements in the form of carriers, which pick up the containers or parisons by means of suitable holding devices, e.g. specially formed gripper elements, at a pick-up location, convey them through the series of successive treatment units, and deliver them finally at a delivery location. The containers are here generally transferred to the plurality of conveyor elements by suitably configured feed conveyors at the pick-up locations and are correspondingly transferred from the plurality of conveyor elements to suitably configured discharge conveyors at the delivery locations. The process line consisting of feed conveyors, container treatment units, discharge conveyors and the parts of the conveyor arrangement connecting these components is normally not provided with any turnout possibilities for the conveyor elements, so that a single damaged conveyor element may stop the entire process line.
In order to operate a conveyor arrangement of such a container treatment system with individually controllable conveyor elements, a plurality of conveyor elements is required for moving the plurality of containers to be treated, which are in engagement with the container treatment system. For keeping the costs for the conveyor elements and thus for the entire container treatment system as low as possible, it is important to use for the conveyor elements a guide and bearing system that is available at the lowest possible price. It must, however, also be guaranteed that, as far as possible, no damaged conveyor element will interfere with the flow of conveyor elements along the process line. To this end, the conveyor elements used must always be maintained in a technically perfect state. Therefore, damaged conveyor elements or wear phenomena of the conveyor elements have to be detected as early as possible. Manual examination and servicing of the conveyor elements by the operating staff is very complicated and time and cost intensive.